Commit graph

1645 commits

Author SHA1 Message Date
Carter Anderson
97d8e4e179 Release 0.5.0 (#1835) 2021-04-06 18:48:48 +00:00
Jakob Hellermann
aaf204cbac remove active camera entity when despawned (#1825)
fixes #1452

This should probably be in 0.5, as the previous workaround isn't possible after dd4a196329 because the hashmap is now private.
2021-04-06 17:09:28 +00:00
Carter Anderson
3118ebdfd3
update changelog (#1829) 2021-04-06 09:58:34 -07:00
François
3e285d5c0b allow deriving bundle for struct with generics with where clause (#1811)
fixes #1777 

Seems the `_where_clause` parameter to lost somewhere, adding it back
2021-04-03 23:30:30 +00:00
François
9098df3034 make pbr shader std140 compatible (#1798)
In shaders, `vec3` should be avoided for `std140` layout, as they take the size of a `vec4` and won't support manual padding by adding an additional `float`.

This change is needed for 3D to work in WebGL2. With it, I get PBR to render
<img width="1407" alt="Screenshot 2021-04-02 at 02 57 14" src="https://user-images.githubusercontent.com/8672791/113368551-5a3c2780-935f-11eb-8c8d-e9ba65b5ee98.png">

Without it, nothing renders... @cart Could this be considered for 0.5 release?

Also, I learned shaders 2 days ago, so don't hesitate to correct any issue or misunderstanding I may have

bevy_webgl2 PR in progress for Bevy 0.5 is here if you want to test: https://github.com/rparrett/bevy_webgl2/pull/1
2021-04-03 23:30:28 +00:00
François
276a81cc30 allow up to 16 parameters for systems (#1805)
fixes #1772 

1st commit: the limit was at 11 as the macro was not using a range including the upper end. I changed that as it feels the purpose of the macro is clearer that way.

2nd commit: as suggested in the `// TODO`, I added a `Config` trait to go to 16 elements tuples. This means that if someone has a custom system parameter with a config that is not a tuple or an `Option`, they will have to implement `Config` for it instead of the standard `Default`.
2021-04-03 23:13:54 +00:00
Jakob Hellermann
1df3b74d38 fix attempt to modify emissive uniform (#1771)
Previously loading the boom box gltf file panic'd with `ERROR: 0:335: 'assign' :  l-value required "anon@7" (can't modify a uniform)`
2021-04-03 22:51:52 +00:00
Carter Anderson
f520a341d5 flip resource scope order (#1793)
I think [collection, thing_removed_from_collection] is a more natural order than [thing_removed_from_collection, collection]. Just a small tweak that I think we should include in 0.5.
2021-04-01 02:24:42 +00:00
TheRawMeatball
b657a9b39f Add on_in_stack_update to SystemSet (#1792) 2021-03-31 20:24:04 +00:00
Carter Anderson
d6bc414bf0 check for duplicate archetypes in QueryState::new_archetype (#1789)
Fixes #1788

See discussion in that issue for details.
2021-03-30 21:21:47 +00:00
François
9193fc57d0 CI break: fix syn version (#1787)
This is a temporary fix for the CI (and anyone building for wasm) break until `wgpu` can update

* `syn` released a version that fixed a bug in how they parsed attributes
* `wasm_bindgen` released a version that uses that fix
* but we're stuck with old `wasm_bindgen` as `wgpu` uses a fixed version: c5ee9cd983/Cargo.toml (L118)

So, to fix this, either we update everyone to latest version of `wasm_bindgen` or we keep using old version of `syn`.

On Bevy side, it should be faster to fix the version of `syn` to one that works.

More details: https://github.com/rustwasm/wasm-bindgen/pull/2510 & https://github.com/rustwasm/wasm-bindgen/issues/2508
2021-03-30 18:34:53 +00:00
Carter Anderson
94c4184068 Text responds to scale factor changes (#1769)
Fixes #1768

If the scale factor changes, queue up all text to be drawn instead of just changed text.
2021-03-27 03:03:47 +00:00
Jonas Matser
9a78addff0 Add PBR textures (#1632)
This PR adds normal maps on top of PBR #1554. Once that PR lands, the changes should look simpler.

Edit: Turned out to be so little extra work, I added metallic/roughness texture too. And occlusion and emissive.

Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2021-03-26 21:00:34 +00:00
davier
0c374df712 Add insert_children and push_children to EntityMut (#1728)
The only API to add a parent/child relationship between existing entities is through commands, there is no easy way to do it from `World`. Manually inserting the components is not completely possible since `PreviousParent` has no public constructor.

This PR adds two methods to set entities as children of an `EntityMut`: `insert_children` and `push_children`. ~~The API is similar to the one on `Commands`, except that the parent is the `EntityMut`.~~ The API is the same as in #1703.
However, the `Parent` and `Children` components are defined in `bevy_transform` which depends on `bevy_ecs`, while `EntityMut` is defined in `bevy_ecs`, so the methods are added to the `BuildWorldChildren` trait instead.
If #1545 is merged this should be fixed too.

I'm aware cart was experimenting with entity hierarchies, but unless it's a coming soon this PR would be useful to have meanwhile.

Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2021-03-26 20:03:12 +00:00
François
d90d19f1c7 gltf: load normal and occlusion as linear textures (#1762)
Load textures from gltf as linear when needed.

This is for #1632, but can be done independently and won't have any visible impact before.

* during iteration over materials, register textures that need to be loaded as linear
* during iteration over textures
  * directly load bytes from external files instead of adding them as dependencies in the load context
  * configure the texture the same way for buffered and external textures
  * if the texture is linear rgb, set as linear rgb
2021-03-26 18:47:47 +00:00
Ixentus
80bd378aa0 Fix tiny state docs inconsistency (#1764)
@TheRawMeatball
2021-03-26 18:30:28 +00:00
Carter Anderson
7a511394ac Add register_component to AppBuilder and improve error message (#1750) 2021-03-26 04:15:07 +00:00
Alexander Sepity
500d7469e7 Fixed criteria-less systems being re-ran unnecessarily (#1754)
Fixes #1753.

The problem was introduced while reworking the logic around stages' own criteria. Before #1675 they used to be stored and processed inline with the systems' criteria, and systems without criteria used that of their stage. After, criteria-less systems think they should run, always. This PR more or less restores previous behavior; a less cludge solution can wait until after 0.5 - ideally, until stageless.

Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2021-03-26 00:31:58 +00:00
Carter Anderson
bf053218bf Disable frustum culling and add warning (#1761)
Frustum culling has some pretty major gaps right now (such as not supporting sprite transform scaling and not taking into account projections). It should be disabled by default until it provides a solid experience across all bevy use cases.
2021-03-25 22:05:28 +00:00
Jakob Hellermann
ad60046982 fix clippy lints (#1756) 2021-03-25 20:48:18 +00:00
Carter Anderson
1d7196da4f Add state app builder docs (#1746)
This is intended to help protect users against #1671. It doesn't resolve the issue, but I think its a good stop-gap solution for 0.5. A "full" fix would be very involved (and maybe not worth the added complexity).
2021-03-25 06:12:14 +00:00
Carter Anderson
80961d1bd0 Fix sparse insert (#1748)
Removing the checks on this line https://github.com/bevyengine/bevy/blob/main/crates/bevy_sprite/src/frustum_culling.rs#L64 and running the "many_sprites" example revealed two corner case bugs in bevy_ecs. The first, a simple and honest missed line introduced in #1471. The other, an insidious monster that has been there since the ECS v2 rewrite, just waiting for the time to strike:

1. #1471 accidentally removed the "insert" line for sparse set components with the "mutated" bundle state. Re-adding it fixes the problem. I did a slight refactor here to make the implementation simpler and remove a branch.
2. The other issue is nastier. ECS v2 added an "archetype graph". When determining what components were added/mutated during an archetype change, we read the FromBundle edge (which encodes this state) on the "new" archetype.  The problem is that unlike "add edges" which are guaranteed to be unique for a given ("graph node", "bundle id") pair, FromBundle edges are not necessarily unique:

```rust
// OLD_ARCHETYPE -> NEW_ARCHETYPE

// [] -> [usize]
e.insert(2usize);
// [usize] -> [usize, i32]
e.insert(1i32);
// [usize, i32] -> [usize, i32]
e.insert(1i32);
// [usize, i32] -> [usize]
e.remove::<i32>();
// [usize] -> [usize, i32]
e.insert(1i32);
```

Note that the second `e.insert(1i32)` command has a different "archetype graph edge" than the first, but they both lead to the same "new archetype".

The fix here is simple: just remove FromBundle edges because they are broken and store the information in the "add edges", which are guaranteed to be unique.

FromBundle edges were added to cut down on the number of archetype accesses / make the archetype access patterns nicer. But benching this change resulted in no significant perf changes and the addition of get_2_mut() for archetypes resolves the access pattern issue.
2021-03-25 05:56:00 +00:00
TheRawMeatball
78edec2e45 Change State::*_next to *_replace, add proper next (#1676)
In the current impl, next clears out the entire stack and replaces it with a new state. This PR moves this functionality into a replace method, and changes the behavior of next to only change the top state.

Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2021-03-25 03:28:40 +00:00
Aaron Winter
621cba4864 Example for 2D Frustum Culling (#1503)
This adds a new project for showing off Frustum Culling.
(Master runs this at sub 1 FPS while with the frustum culling it runs at 144 FPS on my system)

Short clip of the project running:
https://streamable.com/vvzh2u
2021-03-25 01:46:22 +00:00
Aaron Winter
b65ec82d46 Frustum Culling (for Sprites) (#1492)
This PR adds two systems to the sprite module that culls Sprites and AtlasSprites that are not within the camera's view.
This is achieved by removing / adding a new  `Viewable` Component dynamically.

Some of the render queries now use a `With<Viewable>` filter to only process the sprites that are actually on screen, which improves performance drastically for scene swith a large amount of sprites off-screen.

https://streamable.com/vvzh2u

This scene shows a map with a 320x320 tiles, with a grid size of 64p.
This is exactly 102400 Sprites in the entire scene.

Without this PR, this scene runs with 1 to 4 FPS.

With this PR..
.. at 720p, there are around 600 visible sprites and runs at ~215 FPS
.. at 1440p there are around 2000 visible sprites and runs at ~135 FPS

The Systems this PR adds take around 1.2ms (with 100K+ sprites in the scene)

Note:
This is only implemented for Sprites and AtlasTextureSprites.
There is no culling for 3D in this PR.

Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2021-03-24 21:29:53 +00:00
Alexander Sepity
d3e020a1e7 System sets and run criteria v2 (#1675)
I'm opening this prematurely; consider this an RFC that predates RFCs and therefore not super-RFC-like.

This PR does two "big" things: decouple run criteria from system sets, reimagine system sets as weapons of mass system description.

### What it lets us do:

* Reuse run criteria within a stage.
* Pipe output of one run criteria as input to another.
* Assign labels, dependencies, run criteria, and ambiguity sets to many systems at the same time.

### Things already done:
* Decoupled run criteria from system sets.
* Mass system description superpowers to `SystemSet`.
* Implemented `RunCriteriaDescriptor`.
* Removed `VirtualSystemSet`.
* Centralized all run criteria of `SystemStage`.
* Extended system descriptors with per-system run criteria.
* `.before()` and `.after()` for run criteria.
* Explicit order between state driver and related run criteria. Fixes #1672.
* Opt-in run criteria deduplication; default behavior is to panic.
* Labels (not exposed) for state run criteria; state run criteria are deduplicated.

### API issues that need discussion:

* [`FixedTimestep::step(1.0).label("my label")`](eaccf857cd/crates/bevy_ecs/src/schedule/run_criteria.rs (L120-L122)) and [`FixedTimestep::step(1.0).with_label("my label")`](eaccf857cd/crates/bevy_core/src/time/fixed_timestep.rs (L86-L89)) are both valid but do very different things.

---

I will try to maintain this post up-to-date as things change. Do check the diffs in "edited" thingy from time to time.

Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2021-03-24 20:11:55 +00:00
TheRawMeatball
10ef750899 Expose resource change detection on World (#1715) 2021-03-24 01:00:13 +00:00
Rob Parrett
1c573de4f9 Fix panic in multiple_windows example (#1737)
Fixes #1736

There seemed to be an obvious transcription error where `setup_pipeline` was being called during `on_update` of `AppState::CreateWindow` instead of `AppState::Setup`.

However, the example still panicked after fixing that.

I'm not sure if there's some intended or unintended change in event processing during state transitions or something, but this PR make the example work again.

Cleaned up an unused `Stage` label while I was in there.

Please feel free to close this in favor of another approach.
2021-03-24 00:39:54 +00:00
François
248ec1ed95 update rectangle-pack to latest release (#1742)
update to release of rectangle-pack  0.3.0 after #1741
2021-03-24 00:21:37 +00:00
Nolan Darilek
9c252e904a Add LogPlugin, otherwise the ambiguity detector doesn't work. (#1740) 2021-03-23 20:29:28 +00:00
François
9ae56e8604 update for rectangle-pack 0.2.1 (fix CI) (#1741)
crate `rectangle-pack` just published version 0.2.1 with a breaking change: c9ecd58f7a

I also opened an issue on their repo so that they are aware of it: https://github.com/chinedufn/rectangle-pack/issues/3
2021-03-23 19:07:33 +00:00
TheRawMeatball
47004dfcb4 Added remove_non_send to World (#1716)
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2021-03-23 00:41:54 +00:00
Carter Anderson
81b53d15d4 Make Commands and World apis consistent (#1703)
Resolves #1253 #1562

This makes the Commands apis consistent with World apis. This moves to a "type state" pattern (like World) where the "current entity" is stored in an `EntityCommands` builder.

In general this tends to cuts down on indentation and line count. It comes at the cost of needing to type `commands` more and adding more semicolons to terminate expressions.

I also added `spawn_bundle` to Commands because this is a common enough operation that I think its worth providing a shorthand.
2021-03-23 00:23:40 +00:00
François
94f45586ce alien-cake-addict example: ensure the cake doesn't spawn on the player (#1713)
fixes #1707 

In the game, it makes sense to never spawn the cake on the player.
2021-03-22 19:07:15 +00:00
Jakob Hellermann
2dd2e5e9fe make ComponentTicks::set_changed public (#1711)
fixes #1710
2021-03-22 18:49:26 +00:00
Rob Parrett
3dc7b685ab Fix #1704 (#1705)
So I think that the underlying issue is actually a system order ambiguity thing between `spawn_bonus` and `rotate_bonus`, but I'm not confident enough about `run_criteria`, `FixedTimeStep`, etc. to sort that out.
2021-03-22 18:27:52 +00:00
Jonas Matser
cd8025d0a7 Remove remaining camerapos bindings (#1708)
Fixes #1706

@JeanMertz already solved it. I just ran all examples and tests.
2021-03-22 18:10:35 +00:00
dependabot[bot]
42924d2227 Update fixedbitset requirement from 0.3 to 0.4 (#1726)
Updates the requirements on [fixedbitset](https://github.com/bluss/fixedbitset) to permit the latest version.
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2021-03-22 07:06:04 +00:00
Jonas Matser
45b2db7070 Rebase of existing PBR work (#1554)
This is a rebase of StarArawns PBR work from #261 with IngmarBitters work from #1160 cherry-picked on top.

I had to make a few minor changes to make some intermediate commits compile and the end result is not yet 100% what I expected, so there's a bit more work to do.

Co-authored-by: John Mitchell <toasterthegamer@gmail.com>
Co-authored-by: Ingmar Bitter <ingmar.bitter@gmail.com>
2021-03-20 03:22:33 +00:00
Carter Anderson
b6be8a5314 Fix table reserve logic (#1698)
Fixes #1692
Alternative to #1696

This ensures that the capacity actually grows in increments of grow_amount, and also ensures that Table capacity is always <= column and entity vec capacity.

Debug logs that describe the new logic (running the example in #1692)
[out.txt](https://github.com/bevyengine/bevy/files/6173808/out.txt)
2021-03-19 23:32:31 +00:00
MinerSebas
c78b76bba8 Provide better size_hint for QueryIter (#1697)
This PR overrides the default size_hint for QueryIter.
This is mainly done to provide inline documentation of Issue #1686.
2021-03-19 20:52:44 +00:00
Carter Anderson
dd4a196329 Flexible camera bindings (#1689)
Alternative to #1203 and #1611

Camera bindings have historically been "hacked in". They were _required_ in all shaders and only supported a single Mat4. PBR (#1554) requires the CameraView matrix, but adding this using the "hacked" method forced users to either include all possible camera data in a single binding (#1203) or include all possible bindings (#1611).

This approach instead assigns each "active camera" its own RenderResourceBindings, which are populated by CameraNode. The PassNode then retrieves (and initializes) the relevant bind groups for all render pipelines used by visible entities. 

* Enables any number of camera bindings , including zero (with any set or binding number ... set 0 should still be used to avoid rebinds).
* Renames Camera binding to CameraViewProj
* Adds CameraView binding
2021-03-19 20:36:40 +00:00
Alice Cecile
6121e5f933 Reliable change detection (#1471)
# Problem Definition

The current change tracking (via flags for both components and resources) fails to detect changes made by systems that are scheduled to run earlier in the frame than they are.

This issue is discussed at length in [#68](https://github.com/bevyengine/bevy/issues/68) and [#54](https://github.com/bevyengine/bevy/issues/54).

This is very much a draft PR, and contributions are welcome and needed.

# Criteria
1. Each change is detected at least once, no matter the ordering.
2. Each change is detected at most once, no matter the ordering.
3. Changes should be detected the same frame that they are made.
4. Competitive ergonomics. Ideally does not require opting-in.
5. Low CPU overhead of computation.
6. Memory efficient. This must not increase over time, except where the number of entities / resources does.
7. Changes should not be lost for systems that don't run.
8. A frame needs to act as a pure function. Given the same set of entities / components it needs to produce the same end state without side-effects.

**Exact** change-tracking proposals satisfy criteria 1 and 2.
**Conservative** change-tracking proposals satisfy criteria 1 but not 2.
**Flaky** change tracking proposals satisfy criteria 2 but not 1.

# Code Base Navigation

There are three types of flags: 
- `Added`: A piece of data was added to an entity / `Resources`.
- `Mutated`: A piece of data was able to be modified, because its `DerefMut` was accessed
- `Changed`: The bitwise OR of `Added` and `Changed`

The special behavior of `ChangedRes`, with respect to the scheduler is being removed in [#1313](https://github.com/bevyengine/bevy/pull/1313) and does not need to be reproduced.

`ChangedRes` and friends can be found in "bevy_ecs/core/resources/resource_query.rs".

The `Flags` trait for Components can be found in "bevy_ecs/core/query.rs".

`ComponentFlags` are stored in "bevy_ecs/core/archetypes.rs", defined on line 446.

# Proposals

**Proposal 5 was selected for implementation.**

## Proposal 0: No Change Detection

The baseline, where computations are performed on everything regardless of whether it changed.

**Type:** Conservative

**Pros:**
- already implemented
- will never miss events
- no overhead

**Cons:**
- tons of repeated work
- doesn't allow users to avoid repeating work (or monitoring for other changes)

## Proposal 1: Earlier-This-Tick Change Detection

The current approach as of Bevy 0.4. Flags are set, and then flushed at the end of each frame.

**Type:** Flaky

**Pros:**
- already implemented
- simple to understand
- low memory overhead (2 bits per component)
- low time overhead (clear every flag once per frame)

**Cons:**
- misses systems based on ordering
- systems that don't run every frame miss changes
- duplicates detection when looping
- can lead to unresolvable circular dependencies

## Proposal 2: Two-Tick Change Detection

Flags persist for two frames, using a double-buffer system identical to that used in events.

A change is observed if it is found in either the current frame's list of changes or the previous frame's.

**Type:** Conservative

**Pros:**
- easy to understand
- easy to implement
- low memory overhead (4 bits per component)
- low time overhead (bit mask and shift every flag once per frame)

**Cons:**
- can result in a great deal of duplicated work
- systems that don't run every frame miss changes
- duplicates detection when looping

## Proposal 3: Last-Tick Change Detection

Flags persist for two frames, using a double-buffer system identical to that used in events.

A change is observed if it is found in the previous frame's list of changes.

**Type:** Exact

**Pros:**
- exact
- easy to understand
- easy to implement
- low memory overhead (4 bits per component)
- low time overhead (bit mask and shift every flag once per frame)

**Cons:**
- change detection is always delayed, possibly causing painful chained delays
- systems that don't run every frame miss changes
- duplicates detection when looping

## Proposal 4: Flag-Doubling Change Detection

Combine Proposal 2 and Proposal 3. Differentiate between `JustChanged` (current behavior) and `Changed` (Proposal 3).

Pack this data into the flags according to [this implementation proposal](https://github.com/bevyengine/bevy/issues/68#issuecomment-769174804).

**Type:** Flaky + Exact

**Pros:**
- allows users to acc
- easy to implement
- low memory overhead (4 bits per component)
- low time overhead (bit mask and shift every flag once per frame)

**Cons:**
- users must specify the type of change detection required
- still quite fragile to system ordering effects when using the flaky `JustChanged` form
- cannot get immediate + exact results
- systems that don't run every frame miss changes
- duplicates detection when looping

## [SELECTED] Proposal 5: Generation-Counter Change Detection

A global counter is increased after each system is run. Each component saves the time of last mutation, and each system saves the time of last execution. Mutation is detected when the component's counter is greater than the system's counter. Discussed [here](https://github.com/bevyengine/bevy/issues/68#issuecomment-769174804). How to handle addition detection is unsolved; the current proposal is to use the highest bit of the counter as in proposal 1.

**Type:** Exact (for mutations), flaky (for additions)

**Pros:**
- low time overhead (set component counter on access, set system counter after execution)
- robust to systems that don't run every frame
- robust to systems that loop

**Cons:**
- moderately complex implementation
- must be modified as systems are inserted dynamically
- medium memory overhead (4 bytes per component + system)
- unsolved addition detection

## Proposal 6: System-Data Change Detection

For each system, track which system's changes it has seen. This approach is only worth fully designing and implementing if Proposal 5 fails in some way.  

**Type:** Exact

**Pros:**
- exact
- conceptually simple

**Cons:**
- requires storing data on each system
- implementation is complex
- must be modified as systems are inserted dynamically

## Proposal 7: Total-Order Change Detection

Discussed [here](https://github.com/bevyengine/bevy/issues/68#issuecomment-754326523). This proposal is somewhat complicated by the new scheduler, but I believe it should still be conceptually feasible. This approach is only worth fully designing and implementing if Proposal 5 fails in some way.  

**Type:** Exact

**Pros:**
- exact
- efficient data storage relative to other exact proposals

**Cons:**
- requires access to the scheduler
- complex implementation and difficulty grokking
- must be modified as systems are inserted dynamically

# Tests

- We will need to verify properties 1, 2, 3, 7 and 8. Priority: 1 > 2 = 3 > 8 > 7
- Ideally we can use identical user-facing syntax for all proposals, allowing us to re-use the same syntax for each.
- When writing tests, we need to carefully specify order using explicit dependencies.
- These tests will need to be duplicated for both components and resources.
- We need to be sure to handle cases where ambiguous system orders exist.

`changing_system` is always the system that makes the changes, and `detecting_system` always detects the changes.

The component / resource changed will be simple boolean wrapper structs.

## Basic Added / Mutated / Changed

2 x 3 design:
- Resources vs. Components
- Added vs. Changed vs. Mutated
- `changing_system` runs before `detecting_system`
- verify at the end of tick 2

## At Least Once

2 x 3 design:
- Resources vs. Components
- Added vs. Changed vs. Mutated
- `changing_system` runs after `detecting_system`
- verify at the end of tick 2

## At Most Once

2 x 3 design:
- Resources vs. Components
- Added vs. Changed vs. Mutated
- `changing_system` runs once before `detecting_system`
- increment a counter based on the number of changes detected
- verify at the end of tick 2

## Fast Detection
2 x 3 design:
- Resources vs. Components
- Added vs. Changed vs. Mutated
- `changing_system` runs before `detecting_system`
- verify at the end of tick 1

## Ambiguous System Ordering Robustness
2 x 3 x 2 design:
- Resources vs. Components
- Added vs. Changed vs. Mutated
- `changing_system` runs [before/after] `detecting_system` in tick 1
- `changing_system` runs [after/before] `detecting_system` in tick 2

## System Pausing
2 x 3 design:
- Resources vs. Components
- Added vs. Changed vs. Mutated
- `changing_system` runs in tick 1, then is disabled by run criteria
- `detecting_system` is disabled by run criteria until it is run once during tick 3
- verify at the end of tick 3

## Addition Causes Mutation

2 design:
- Resources vs. Components
- `adding_system_1` adds a component / resource
- `adding system_2` adds the same component / resource
- verify the `Mutated` flag at the end of the tick
- verify the `Added` flag at the end of the tick

First check tests for: https://github.com/bevyengine/bevy/issues/333
Second check tests for: https://github.com/bevyengine/bevy/issues/1443

## Changes Made By Commands

- `adding_system` runs in Update in tick 1, and sends a command to add a component 
- `detecting_system` runs in Update in tick 1 and 2, after `adding_system`
- We can't detect the changes in tick 1, since they haven't been processed yet
- If we were to track these changes as being emitted by `adding_system`, we can't detect the changes in tick 2 either, since `detecting_system` has already run once after `adding_system` :( 

# Benchmarks

See: [general advice](https://github.com/bevyengine/bevy/blob/master/docs/profiling.md), [Criterion crate](https://github.com/bheisler/criterion.rs)

There are several critical parameters to vary: 
1. entity count (1 to 10^9)
2. fraction of entities that are changed (0% to 100%)
3. cost to perform work on changed entities, i.e. workload (1 ns to 1s)

1 and 2 should be varied between benchmark runs. 3 can be added on computationally.

We want to measure:
- memory cost
- run time

We should collect these measurements across several frames (100?) to reduce bootup effects and accurately measure the mean, variance and drift.

Entity-component change detection is much more important to benchmark than resource change detection, due to the orders of magnitude higher number of pieces of data.

No change detection at all should be included in benchmarks as a second control for cases where missing changes is unacceptable.

## Graphs
1. y: performance, x: log_10(entity count), color: proposal, facet: performance metric. Set cost to perform work to 0. 
2. y: run time, x: cost to perform work, color: proposal, facet: fraction changed. Set number of entities to 10^6
3. y: memory, x: frames, color: proposal

# Conclusions
1. Is the theoretical categorization of the proposals correct according to our tests?
2. How does the performance of the proposals compare without any load?
3. How does the performance of the proposals compare with realistic loads?
4. At what workload does more exact change tracking become worth the (presumably) higher overhead?
5. When does adding change-detection to save on work become worthwhile?
6. Is there enough divergence in performance between the best solutions in each class to ship more than one change-tracking solution?

# Implementation Plan

1. Write a test suite.
2. Verify that tests fail for existing approach.
3. Write a benchmark suite.
4. Get performance numbers for existing approach.
5. Implement, test and benchmark various solutions using a Git branch per proposal.
6. Create a draft PR with all solutions and present results to team.
7. Select a solution and replace existing change detection.

Co-authored-by: Brice DAVIER <bricedavier@gmail.com>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2021-03-19 17:53:26 +00:00
François
348e2a3d40 documentation on Transform and GlobalTransform (#1687)
fixes #1599 

* Added doc on `Transform` and `GlobalTransform` to describe usage and how `GlobalTransform` is updated
* Documented all methods on `Transform`
* `#[doc(hidden)]` most constructors and methods mutating `GlobalTransform`, documented the other
* Mentioned z-ordering for `Transform` in 2d
2021-03-19 03:54:53 +00:00
Carter Anderson
8d1e52be31 fix dyn warning (#1690)
This is now a warning on nightly.
2021-03-19 02:53:26 +00:00
Zaszi
0a875f647d Derive PartialEq for WindowMode (#1688)
Many a game will provide some sort of video settings where a window mode option is a common inclusion. I ran into problems, however, with [egui's](https://github.com/emilk/egui) `combo_box` that imposes a `PartialEq` necessity. Deriving the trait would fix this problem, and as this does not break any existing API it should be a non-controversial change.
2021-03-18 23:47:34 +00:00
Alec Deason
cd4c684ad5 Fix tiny typo in ambiguity checker message (#1682)
Add one missing word
2021-03-18 01:28:21 +00:00
François
bcd5318247 color spaces and representation (#1572)
`Color` can now be from different color spaces or representation:
- sRGB
- linear RGB
- HSL

This fixes #1193 by allowing the creation of const colors of all types, and writing it to the linear RGB color space for rendering.

I went with an enum after trying with two different types (`Color` and `LinearColor`) to be able to use the different variants in all place where a `Color` is expected.

I also added the HLS representation because:
- I like it
- it's useful for some case, see example `contributors`: I can just change the saturation and lightness while keeping the hue of the color
- I think adding another variant not using `red`, `green`, `blue` makes it clearer there are differences

Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2021-03-17 23:59:51 +00:00
Alice Cecile
ab0165d20d Improved documentation for Events (#1669)
Explains subtle behavior more explicitly, documents `add_event`, mentions `EventWriter`.

Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2021-03-17 23:42:19 +00:00
Carter Anderson
5fedb6029a Make Reflect impls unsafe (Reflect::any must return self) (#1679)
Fixes #1100 

Implementors must make sure that `Reflect::any` and `Reflect::any_mut` both return the `self` reference passed in (both for logical correctness and downcast safety).
2021-03-17 22:46:46 +00:00